But as Hamilton Nolan details at Splinter after attending several Biden rallies, he’s also clearly losing some of his verbal fluency. It “is impossible not to notice that Joe is getting old. Any reporter who doesn’t note this is not telling you the whole truth about what they witness,” he writes. “Biden is not senile, or unable to function, but the signs of the slow creep of cognitive decline are too visible to ignore.” Even some attempts to do damage control — like reassurances from Biden’s brain surgeon who saved him from two aneurysms 31 years ago that he is in fine shape — are less than convincing.

What’s more, Biden produces a steady stream of these embarrassing verbal flubs. At the conclusion of the most recent debate he tried to get supporters to text “JOE” to a number to send him money, but forgot the texting part and nonsensically said “go to Joe 30330” instead. After the shootings in El Paso and Dayton, he referenced “the tragic events in Houston today and also in Michigan” before correcting himself. More than once he has referred to Margaret Thatcher (who died in 2013) as prime minister of the U.K. Here he is talking about his time serving with “Raprock” Obama. There are many similar stories.

If Biden is the nominee, I can all but guarantee that this will be one of the biggest two or three stories of the campaign.